﻿<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>GoJS Tree View with Check Boxes</title>
<meta name="description" content="A traditional tree view using TreeLayout with tri-state checkboxes showing partially checked subtrees." />
<!-- Copyright 1998-2019 by Northwoods Software Corporation. -->
<meta charset="UTF-8">
<script src="../release/go.js"></script>
<script src="../assets/js/goSamples.js"></script>  <!-- this is only for the GoJS Samples framework -->
<script id="code">

  // This button assumes data binding to the "checked" property.
  go.GraphObject.defineBuilder("TriStateCheckBoxButton", function (args) {
    var button = /** @type {Panel} */ (
      go.GraphObject.make("Button",
        {
          "ButtonBorder.fill": "white",
          width: 14,
          height: 14
        },
        go.GraphObject.make(go.Shape,
          {
            name: "ButtonIcon",
            geometryString: 'M0 0 M0 8.85 L4.9 13.75 16.2 2.45 M16.2 16.2',  // a 'check' mark
            strokeWidth: 2,
            stretch: go.GraphObject.Fill,  // this Shape expands to fill the Button
            geometryStretch: go.GraphObject.Uniform,  // the check mark fills the Shape without distortion
            background: null,
            visible: false  // visible set to false: not checked, unless data.checked is true
          },
          new go.Binding("visible", "checked", function (p) { return p === true || p === null; }),
          new go.Binding("stroke", "checked", function (p) { return p === null ? null : "black"; }),
          new go.Binding("background", "checked", function (p) { return p === null ? "gray" : null; })
        )
      )
    );

    function updateCheckBoxesDown(node, val) {
      node.diagram.model.setDataProperty(node.data, "checked", val);
      node.findTreeChildrenNodes().each(function (child) { updateCheckBoxesDown(child, val); })
    }

    function updateCheckBoxesUp(node) {
      var parent = node.findTreeParentNode();
      if (parent !== null) {
        var anychecked = parent.findTreeChildrenNodes().any(function (n) { return n.data.checked !== false && n.data.checked !== undefined; });
        var allchecked = parent.findTreeChildrenNodes().all(function (n) { return n.data.checked === true; });
        node.diagram.model.setDataProperty(parent.data, "checked", (allchecked ? true : (anychecked ? null : false)));
        updateCheckBoxesUp(parent);
      }
    }

    button.click = function (e, button) {
      if (!button.isEnabledObject()) return;
      var diagram = e.diagram;
      if (diagram === null || diagram.isReadOnly) return;
      if (diagram.model.isReadOnly) return;
      e.handled = true;
      var shape = button.findObject("ButtonIcon");
      diagram.startTransaction("checkbox");
      // Assume the name of the data property is "checked".
      var node = button.part;
      var oldval = node.data.checked;
      var newval = (oldval !== true);  // newval will always be either true or false, never null
      // Set this data.checked property and those of all its children to the same value
      updateCheckBoxesDown(node, newval);
      // Walk up the tree and update all of their checkboxes
      updateCheckBoxesUp(node);
      // support extra side-effects without clobbering the click event handler:
      if (typeof button["_doClick"] === "function") button["_doClick"](e, button);
      diagram.commitTransaction("checkbox");
    };

    return button;
  });

  function init() {
    if (window.goSamples) goSamples();  // init for these samples -- you don't need to call this
    var $ = go.GraphObject.make;  // for conciseness in defining templates

    myDiagram =
      $(go.Diagram, "myDiagramDiv",
        {
          allowMove: false,
          allowCopy: false,
          allowDelete: false,
          allowHorizontalScroll: false,
          layout:
            $(go.TreeLayout,
              {
                alignment: go.TreeLayout.AlignmentStart,
                angle: 0,
                compaction: go.TreeLayout.CompactionNone,
                layerSpacing: 16,
                layerSpacingParentOverlap: 1,
                nodeIndentPastParent: 1.0,
                nodeSpacing: 0,
                setsPortSpot: false,
                setsChildPortSpot: false
              })
      });

    myDiagram.nodeTemplate =
      $(go.Node,
        { // no Adornment: instead change panel background color by binding to Node.isSelected
          selectionAdorned: false,
          // a custom function to allow expanding/collapsing on double-click
          // this uses similar logic to a TreeExpanderButton
          doubleClick: function(e, node) {
            var cmd = myDiagram.commandHandler;
            if (node.isTreeExpanded) {
              if (!cmd.canCollapseTree(node)) return;
            } else {
              if (!cmd.canExpandTree(node)) return;
            }
            e.handled = true;
            if (node.isTreeExpanded) {
              cmd.collapseTree(node);
            } else {
              cmd.expandTree(node);
            }
          }
        },
        $("TreeExpanderButton",
          {
            width: 14,
            "ButtonBorder.fill": "whitesmoke",
            "ButtonBorder.stroke": "lightgray",
            "_buttonFillOver": "rgba(0,128,255,0.25)",
            "_buttonStrokeOver": null,
            "_buttonFillPressed": "rgba(0,128,255,0.4)"
          }),
        $(go.Panel, "Horizontal",
          { position: new go.Point(16, 0), margin: new go.Margin(0, 2, 0, 0), defaultAlignment: go.Spot.Center },
          new go.Binding("background", "isSelected", function(s) { return (s ? "lightblue" : "white"); }).ofObject(),
          $("TriStateCheckBoxButton"),
          $(go.TextBlock,
            { font: '9pt Verdana, sans-serif', margin: new go.Margin(0, 0, 0, 2) },
            new go.Binding("text", "key", function(s) { return "item " + s; }))
        )  // end Horizontal Panel
      );  // end Node

    // without lines
    //myDiagram.linkTemplate = $(go.Link);

    // with lines
    myDiagram.linkTemplate =
      $(go.Link,
        { selectable: false,
          routing: go.Link.Orthogonal,
          fromEndSegmentLength: 4,
          toEndSegmentLength: 4,
          fromSpot: new go.Spot(0.001, 1, 7, 0),
          toSpot: go.Spot.Left },
        $(go.Shape,
          { stroke: 'gray', strokeDashArray: [1,2] }));

    // create a random tree
    var nodeDataArray = [{ key: 0 }];
    var max = 25;
    var count = 0;
    while (count < max) {
      count = makeTree(3, count, max, nodeDataArray, nodeDataArray[0]);
    }
    myDiagram.model = new go.TreeModel(nodeDataArray);
  }

  function makeTree(level, count, max, nodeDataArray, parentdata) {
    var numchildren = Math.floor(Math.random() * 10);
    for (var i = 0; i < numchildren; i++) {
      if (count >= max) return count;
      count++;
      var childdata = { key: count, parent: parentdata.key };
      nodeDataArray.push(childdata);
      if (level > 0 && Math.random() > 0.5) {
        count = makeTree(level - 1, count, max, nodeDataArray, childdata);
      }
    }
    return count;
  }
</script>
</head>
<body onload="init()">
<div id="sample">
  <div id="myDiagramDiv" style="border: 1px solid black; width: 400px; height: 500px"></div>
  <p>
    This sample is derived from the <a href="treeView.html" target="_blank">Tree View</a> sample.
    It adds the definition of the "TriStateCheckBoxButton" which is defined only to be used in a tree.
  </p>
</div>
</body>
</html>
